Spiral

In which the gang, plus Spike and the girlfriends, flee town in a Winnebago while being pursued by the Knights of Byzantium until they hole up in an abandoned gas station where they call Ben in to tend to a wounded Giles and he turns into Glory and steals away with Dawn. That's right - a Winnebago.

Official back-of-box synopsis:

Buffy and the gang go on the run after Glory discovers that Dawn is the Key. Escaping Sunnydale, the gang battles the Knights of Byzantium. Soon Buffy learns the secret behind Glory and the Key.

From the old WB Buffy website:

BUFFY AND THE GANG FLEE SUNNYDALE - Buffy explodes into action and takes the gang on the road once Glory discovers that Dawn is the Key with Glory on their tail blazing a path of destruction. While on the run, things happen fast as Giles and Spike are wounded, Dawn learns she has the power to destroy the universe, and Willow stays close to an incoherent Tara.

Links:

This episode's page at http://www.restlessbtvs.com/, the Restless BTVS Trivia Guide

This episode's page at http://www.vrya.net/bdb/, the Buffyverse Dialog Database

Cross-reference:

episodes in which humans die in conflict with Buffy:

• The Pack
  the Zookeeper
• What's My Line? (part 1)
  the assassin at the ice-rink
• Go Fish
  Coach Marin and Nurse Greenleigh
• Homecoming
  Hans and Frederick Gruenshtahler
• Revelations
  Gwendolyn Post
• this episode
  Some of the Knights: they're human, right?

Cast:

• Sarah Michelle Gellar as Buffy
• Alyson Hannigan as Willow
• Nicholas Brendon as Xander
  

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• Anthony Stewart Head as Giles
• James Marsters as Spike
• Emma Caulfield as Anya
• Amber Benson as Tara
• Michelle Trachtenberg as Dawn
• Bob Morrisey as Crazy Guy
• Charlie Weber as Ben
• Clare Kramer as Glory
• Justin Gorence as Orlando
• Paul Bates as Crazy Guy #2
• Carl J Johnson as Crazy Guy #3
• Todd Duffey as Murk
• Lily Knight as Gronx
• Wade Andrew Williams as Colonel Gregor
• Karim Prince as Dante
• Jack Donner as Cleric #1
• Mary Sheldon as Nurse